Lower‐ and Higher‐Order Nonclassical Properties of Photon Added and Subtracted Displaced Fock States

Nonclassical properties of photon added and subtracted displaced Fock states are studied using various witnesses of lower‐ and higher‐order nonclassicality. Compact analytic expressions are obtained for the nonclassicality witnesses. Using those expressions, it is established that these states and the states that can be obtained as their limiting cases (except coherent states) are highly nonclassical as they show the existence of lower‐ and higher‐order antibunching and sub‐Poissonian photon statistics, in addition to the nonclassical features revealed through the Mandel $Q_M$ parameter, zeros of Q function, Klyshko's criterion, and Agarwal–Tara criterion. Further, some comparison between the nonclassicality of photon added and subtracted displaced Fock states have been performed using witnesses of nonclassicality. This has established that between the two types of non‐Gaussianity inducing operations (i.e., photon addition and subtraction) used here, photon addition influences the nonclassical properties more strongly. Further, optical designs for the generation of photon added and subtracted displaced Fock states from squeezed vacuum state have also been proposed.     

New R-matrices from representations of braid-monoid algebras based on superalgebras

In this paper we discuss representations of the Birman–Wenzl–Murakami algebra as well as of its dilute extension containing several free parameters. These representations are based on superalgebras and their baxterizations permit us to derive novel trigonometric solutions of the graded Yang–Baxter equation. In this way we obtain the multiparametric R-matrices associated to the $U_q[\mathit{sl}{(r|2m)}^{(2)}]$, $U_q[\mathit{osp}{(r|2m)}^{(1)}]$ and $U_q[\mathit{osp}{(r=2n|2m)}^{(2)}]$ quantum symmetries. Two other families of multiparametric R-matrices not predicted before within the context of quantum superalgebras are also presented. The latter systems are indeed non-trivial generalizations of the $U_q[D_{n+1}^{(2)}]$ vertex model when both distinct edge variables statistics and extra free-parameters are admissible.     

One-photon absorption in direct gap semiconductors

One-photon absorption coefficients of InSb and GaAs are calculated using the first order perturbation theory assuming a two band model in which the interband energy difference is given by $E(k)=E_g{(1+\frac{h^2{k}^2}{m^{*E}g})}^{1/2}$ The results obtained are in much better agreement with the experimental data than the results of first order perturbation calculations using parabolic bands.